I'm really stuck on this question. Please help!!!!!!!

Question

How much heat is needed to boil 2.65 kg of water at its boiling point?
Use Q = mass latent heat of vaporization.
Properties of water

Property Value
Melting point 0C
Boiling point 100C
cliquid 4.18 kJ/(kg C)
Latent heat of fusion 333 kJ/kg
Latent heat of vaporization 2260 kJ/kg

A. 11.1 kJ

B. 265 kJ

C. 5990 kJ

D. 882 kJ

Answer 1

A specific latent heat (L) expresses the amount of energy in the form of heat (Q) required to completely effect a phase change of a unit of mass (m), usually 1kg, of a substance as an intensive property:

 

L= Q/m

 

From this definition, the latent heat for a given mass of a substance is calculated by

Q = m L
where:

Q is the amount of energy released or absorbed during the change of phase of the substance (in kJ),
m is the mass of the substance (in kg), and
L is the specific latent heat for a particular substance (kJ-kgm−1), either L is for vaporization or fusion

 

Here in this question L is latent heat for vaporization because water (liquid phase) is changing into vapor

 

Q = 2.65 x 2260 kJ

   = 5989 kJ

 

So the answer is (C) 5990 kJ